In the diagram given below in Fig. A, B and C are three ammeters each of negligible resistance. The ammeter B reads 0-5 A. Calculate:
the total resistance of the circuit,

Explanation

If `R_p` is the equivalent resistance of resistors 6 `Omega ` and 3 `Omega ` connected in parallel, then
`(1)/(R_p) = 1/6 +1/3 =(1+2)/(6) = 3/6`
or ` R_p = 6/3 = 2 Omega `
Now total resistance of the circuit will be the equivalent resistance of the series combination of resistors 2 `Omega` and `R_p (= 2 Omega )`. i.e.,
Total resistance `R_s = 2 + 2 = 4 Omega `